Possibility of FX2LP I2C module operation at 400 KHz?

Yes, the I2C module in FX2LP can operate at 400KHz. The speed of operation is controlled by 400KHz bit of I2CTL register. When this bit is at its default value of 0, SCL will be driven at approximately 100 kHz. Setting this bit to 1 causes the EZ-USB to drive SCL at approximately 400 kHz.